Explanation:
The magnitude of a vector v can be found using Pythagorean's theorem.
||v|| = √(vₓ² + vᵧ²)
||v|| = √((-309)² + (187)²)
||v|| ≈ 361
You can find the angle of a vector using trigonometry.
tan θ = vᵧ / vₓ
tan θ = 187 / -309
θ ≈ 149° or θ ≈ 329°
vₓ is negative and vᵧ is positive, so θ must be in the second quadrant. Therefore, θ ≈ 149°.
Answer:
(a) -472.305 J
(b) 1 m
Explanation:
(a)
Change in mechanical energy equals change in kinetic energy
Kinetic energy is given by
Initial kinetic energy is 
Since he finally comes to rest, final kinetic energy is zero because the final velocity is zero
Change in kinetic energy is given by final kinetic energy- initial kinetic energy hence
0-472.305 J=-472.305 J
(b)
From fundamental kinematic equation

Where v and u are final and initial velocities respectively, a is acceleration, s is distance
Making s the subject we obtain
but a=\mu g hence

Answer:
180°
Explanation:
Friction, if it exists, ALWAYS opposes motion or attempted motion.
Answer:
time is a scalar quantity.
When light passes from one medium to another, part of it continues on
into the new medium, while the rest of it bounces away from the boundary,
back into the first medium.
The part of the light that continues on into the new medium is <em>transmitted</em>
light. Its forward progress at any point in its journey is <em>transmission</em>.
Its direction usually changes as it crosses the boundary. The bending is <em>
refraction</em>.
The part of the light that bounces away from the boundary and heads back
into the first medium is <em>reflected</em> light. The process of bouncing is <em>reflection</em>.